The United States is expressing concern about what it says are candidate-registration problems and harassment of opposition politicians in the run-up to the October presidential elections in Azerbaijan.

The State Department is stressing that the United States does not take a position on, or support, any particular candidate in the October 15 Azerbaijani election.

But it says U.S. officials are "troubled" by recent events in the campaign in the central Asian state, including the denial of candidate registrations, and the arrest of supporters of some candidates.

A State Department spokeswoman, Joanne Prokopowicz, expressed concern about what she said was the harassment of opposition party leaders, including the arrest of associates of Isa Gambar, the presidential candidate of the conservative Musavat Party, and of Ali Karimli of the Peoples Front of Azerbaijan Party or PFAP.

She urged authorities in Baku to cease the harassment, which she said is in keeping with neither Azerbaijani law or the country's international commitments.

She also said the United States has "serious concerns" about the use of violence by authorities in breaking up unsanctioned public demonstrations, and appealed to the government to use restraint and to allow the peaceful public expression of political views.

Ms. Prokopowicz further cited the rejection by the Azerbaijani Central Election Commission of presidential candidacies including that of Rasul Gouliev of the opposition Azerbaijan Democratic Party, a former speaker of the parliament.

She said the commission actions raise serious questions as to whether Azerbaijani law is being applied fairly, and said U.S. concerns are shared by the Organization for Security and Cooperation mission in Baku, Azerbaijani opposition party leaders, and by members of the U.S. Congress.

The United States has been a persistent critic of the human rights record of the government of Azerbaijani President Heydar Aliyev, a Soviet-era communist party leader who was first elected in 1993 and is seeking a third five-year term in office.

In its annual global human rights report issued in March, the State Department said Azerbaijan's human rights record "remained poor" and included restrictions on the freedoms of speech and the press, arbitrary arrests and caseS of torture by police.

It said Mr. Aliyev's last re-election in 1998 was marred by serious irregularities, and that recent national assembly elections and a referendum on constitutional amendments in August of last year were similarly deficient.